1 /* Target-machine dependent code for Motorola MCore for GDB, the GNU debugger
2 Copyright (C) 1999 Free Software Foundation, Inc.
4 This file is part of GDB.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
26 /* Functions declared and used only in this file */
28 static CORE_ADDR
mcore_analyze_prologue (struct frame_info
*fi
, CORE_ADDR pc
, int skip_prologue
);
30 static struct frame_info
*analyze_dummy_frame (CORE_ADDR pc
, CORE_ADDR frame
);
32 static int get_insn (CORE_ADDR pc
);
34 /* Functions exported from this file */
36 int mcore_use_struct_convention (int gcc_p
, struct type
*type
);
38 void _initialize_mcore (void);
40 void mcore_init_extra_frame_info (struct frame_info
*fi
);
42 CORE_ADDR
mcore_frame_saved_pc (struct frame_info
*fi
);
44 CORE_ADDR
mcore_find_callers_reg (struct frame_info
*fi
, int regnum
);
46 CORE_ADDR
mcore_frame_args_address (struct frame_info
*fi
);
48 CORE_ADDR
mcore_frame_locals_address (struct frame_info
*fi
);
50 void mcore_virtual_frame_pointer (CORE_ADDR pc
, long *reg
, long *offset
);
52 CORE_ADDR
mcore_push_return_address (CORE_ADDR pc
, CORE_ADDR sp
);
54 CORE_ADDR
mcore_push_arguments (int nargs
, value_ptr
* args
, CORE_ADDR sp
,
55 unsigned char struct_return
, CORE_ADDR struct_addr
);
57 void mcore_pop_frame (struct frame_info
*fi
);
59 CORE_ADDR
mcore_skip_prologue (CORE_ADDR pc
);
61 CORE_ADDR
mcore_frame_chain (struct frame_info
*fi
);
63 unsigned char *mcore_breakpoint_from_pc (CORE_ADDR
* bp_addr
, int *bp_size
);
65 int mcore_use_struct_convention (int gcc_p
, struct type
*type
);
67 void mcore_store_return_value (struct type
*type
, char *valbuf
);
69 CORE_ADDR
mcore_extract_struct_value_address (char *regbuf
);
71 void mcore_extract_return_value (struct type
*type
, char *regbuf
, char *valbuf
);
77 /* The registers of the Motorola MCore processors */
79 char *mcore_register_names
[] =
80 { "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
81 "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
82 "ar0", "ar1", "ar2", "ar3", "ar4", "ar5", "ar6", "ar7",
83 "ar8", "ar9", "ar10", "ar11", "ar12", "ar13", "ar14", "ar15",
84 "psr", "vbr", "epsr", "fpsr", "epc", "fpc", "ss0", "ss1",
85 "ss2", "ss3", "ss4", "gcr", "gsr", "cr13", "cr14", "cr15",
86 "cr16", "cr17", "cr18", "cr19", "cr20", "cr21", "cr22", "cr23",
87 "cr24", "cr25", "cr26", "cr27", "cr28", "cr29", "cr30", "cr31",
93 /* Additional info that we use for managing frames */
94 struct frame_extra_info
96 /* A generic status word */
99 /* Size of this frame */
102 /* The register that is acting as a frame pointer, if
103 it is being used. This is undefined if status
104 does not contain the flag MY_FRAME_IN_FP. */
108 /* frame_extra_info status flags */
110 /* The base of the current frame is actually in the stack pointer.
111 This happens when there is no frame pointer (MCore ABI does not
112 require a frame pointer) or when we're stopped in the prologue or
113 epilogue itself. In these cases, mcore_analyze_prologue will need
114 to update fi->frame before returning or analyzing the register
115 save instructions. */
116 #define MY_FRAME_IN_SP 0x1
118 /* The base of the current frame is in a frame pointer register.
119 This register is noted in frame_extra_info->fp_regnum.
121 Note that the existance of an FP might also indicate that the
122 function has called alloca. */
123 #define MY_FRAME_IN_FP 0x2
125 /* This flag is set to indicate that this frame is the top-most
126 frame. This tells frame chain not to bother trying to unwind
127 beyond this frame. */
128 #define NO_MORE_FRAMES 0x4
130 /* Instruction macros used for analyzing the prologue */
131 #define IS_SUBI0(x) (((x) & 0xfe0f) == 0x2400) /* subi r0,oimm5 */
132 #define IS_STM(x) (((x) & 0xfff0) == 0x0070) /* stm rf-r15,r0 */
133 #define IS_STWx0(x) (((x) & 0xf00f) == 0x9000) /* stw rz,(r0,disp) */
134 #define IS_STWxy(x) (((x) & 0xf000) == 0x9000) /* stw rx,(ry,disp) */
135 #define IS_MOVx0(x) (((x) & 0xfff0) == 0x1200) /* mov rn,r0 */
136 #define IS_LRW1(x) (((x) & 0xff00) == 0x7100) /* lrw r1,literal */
137 #define IS_MOVI1(x) (((x) & 0xf80f) == 0x6001) /* movi r1,imm7 */
138 #define IS_BGENI1(x) (((x) & 0xfe0f) == 0x3201) /* bgeni r1,imm5 */
139 #define IS_BMASKI1(x) (((x) & 0xfe0f) == 0x2C01) /* bmaski r1,imm5 */
140 #define IS_ADDI1(x) (((x) & 0xfe0f) == 0x2001) /* addi r1,oimm5 */
141 #define IS_SUBI1(x) (((x) & 0xfe0f) == 0x2401) /* subi r1,oimm5 */
142 #define IS_RSUBI1(x) (((x) & 0xfe0f) == 0x2801) /* rsubi r1,imm5 */
143 #define IS_NOT1(x) (((x) & 0xffff) == 0x01f1) /* not r1 */
144 #define IS_ROTLI1(x) (((x) & 0xfe0f) == 0x3801) /* rotli r1,imm5 */
145 #define IS_BSETI1(x) (((x) & 0xfe0f) == 0x3401) /* bseti r1,imm5 */
146 #define IS_BCLRI1(x) (((x) & 0xfe0f) == 0x3001) /* bclri r1,imm5 */
147 #define IS_IXH1(x) (((x) & 0xffff) == 0x1d11) /* ixh r1,r1 */
148 #define IS_IXW1(x) (((x) & 0xffff) == 0x1511) /* ixw r1,r1 */
149 #define IS_SUB01(x) (((x) & 0xffff) == 0x0510) /* subu r0,r1 */
150 #define IS_RTS(x) (((x) & 0xffff) == 0x00cf) /* jmp r15 */
152 #define IS_R1_ADJUSTER(x) \
153 (IS_ADDI1(x) || IS_SUBI1(x) || IS_ROTLI1(x) || IS_BSETI1(x) \
154 || IS_BCLRI1(x) || IS_RSUBI1(x) || IS_NOT1(x) \
155 || IS_IXH1(x) || IS_IXW1(x))
160 mcore_dump_insn (char *commnt
, CORE_ADDR pc
, int insn
)
164 printf_filtered ("MCORE: %s %08x %08x ",
165 commnt
, (unsigned int) pc
, (unsigned int) insn
);
166 (*tm_print_insn
) (pc
, &tm_print_insn_info
);
167 printf_filtered ("\n");
170 #define mcore_insn_debug(args) { if (mcore_debug) printf_filtered args; }
171 #else /* !MCORE_DEBUG */
172 #define mcore_dump_insn(a,b,c) {}
173 #define mcore_insn_debug(args) {}
176 /* Given the address at which to insert a breakpoint (BP_ADDR),
177 what will that breakpoint be?
179 For MCore, we have a breakpoint instruction. Since all MCore
180 instructions are 16 bits, this is all we need, regardless of
181 address. bpkt = 0x0000 */
184 mcore_breakpoint_from_pc (CORE_ADDR
* bp_addr
, int *bp_size
)
186 static char breakpoint
[] =
192 /* Helper function for several routines below. This funtion simply
193 sets up a fake, aka dummy, frame (not a _call_ dummy frame) that
194 we can analyze with mcore_analyze_prologue. */
196 static struct frame_info
*
197 analyze_dummy_frame (CORE_ADDR pc
, CORE_ADDR frame
)
199 static struct frame_info
*dummy
= NULL
;
203 dummy
= (struct frame_info
*) xmalloc (sizeof (struct frame_info
));
204 dummy
->saved_regs
= (CORE_ADDR
*) xmalloc (SIZEOF_FRAME_SAVED_REGS
);
206 (struct frame_extra_info
*) xmalloc (sizeof (struct frame_extra_info
));
212 dummy
->frame
= frame
;
213 dummy
->extra_info
->status
= 0;
214 dummy
->extra_info
->framesize
= 0;
215 memset (dummy
->saved_regs
, '\000', SIZEOF_FRAME_SAVED_REGS
);
216 mcore_analyze_prologue (dummy
, 0, 0);
220 /* Function prologues on the Motorol MCore processors consist of:
222 - adjustments to the stack pointer (r1 used as scratch register)
223 - store word/multiples that use r0 as the base address
224 - making a copy of r0 into another register (a "frame" pointer)
226 Note that the MCore really doesn't have a real frame pointer.
227 Instead, the compiler may copy the SP into a register (usually
228 r8) to act as an arg pointer. For our target-dependent purposes,
229 the frame info's "frame" member will be the beginning of the
230 frame. The SP could, in fact, point below this.
232 The prologue ends when an instruction fails to meet either of
233 the first two criteria or when an FP is made. We make a special
234 exception for gcc. When compiling unoptimized code, gcc will
235 setup stack slots. We need to make sure that we skip the filling
236 of these stack slots as much as possible. This is only done
237 when SKIP_PROLOGUE is set, so that it does not mess up
240 /* Analyze the prologue of frame FI to determine where registers are saved,
241 the end of the prologue, etc. Return the address of the first line
242 of "real" code (i.e., the end of the prologue). */
245 mcore_analyze_prologue (struct frame_info
*fi
, CORE_ADDR pc
, int skip_prologue
)
247 CORE_ADDR func_addr
, func_end
, addr
, stop
;
248 CORE_ADDR stack_size
;
250 int status
, fp_regnum
, flags
;
252 int register_offsets
[NUM_REGS
];
255 /* If provided, use the PC in the frame to look up the
256 start of this function. */
257 pc
= (fi
== NULL
? pc
: fi
->pc
);
259 /* Find the start of this function. */
260 status
= find_pc_partial_function (pc
, &name
, &func_addr
, &func_end
);
262 /* If the start of this function could not be found or if the debbuger
263 is stopped at the first instruction of the prologue, do nothing. */
267 /* If the debugger is entry function, give up. */
268 if (func_addr
== entry_point_address ())
271 fi
->extra_info
->status
|= NO_MORE_FRAMES
;
275 /* At the start of a function, our frame is in the stack pointer. */
276 flags
= MY_FRAME_IN_SP
;
278 /* Start decoding the prologue. We start by checking two special cases:
280 1. We're about to return
281 2. We're at the first insn of the prologue.
283 If we're about to return, our frame has already been deallocated.
284 If we are stopped at the first instruction of a prologue,
285 then our frame has not yet been set up. */
287 /* Get the first insn from memory (all MCore instructions are 16 bits) */
288 mcore_insn_debug (("MCORE: starting prologue decoding\n"));
289 insn
= get_insn (pc
);
290 mcore_dump_insn ("got 1: ", pc
, insn
);
292 /* Check for return. */
293 if (fi
!= NULL
&& IS_RTS (insn
))
295 mcore_insn_debug (("MCORE: got jmp r15"));
296 if (fi
->next
== NULL
)
297 fi
->frame
= read_sp ();
301 /* Check for first insn of prologue */
302 if (fi
!= NULL
&& fi
->pc
== func_addr
)
304 if (fi
->next
== NULL
)
305 fi
->frame
= read_sp ();
309 /* Figure out where to stop scanning */
310 stop
= (fi
? fi
->pc
: func_end
);
312 /* Don't walk off the end of the function */
313 stop
= (stop
> func_end
? func_end
: stop
);
315 /* REGISTER_OFFSETS will contain offsets, from the top of the frame
316 (NOT the frame pointer), for the various saved registers or -1
317 if the register is not saved. */
318 for (rn
= 0; rn
< NUM_REGS
; rn
++)
319 register_offsets
[rn
] = -1;
321 /* Analyze the prologue. Things we determine from analyzing the
323 * the size of the frame
324 * where saved registers are located (and which are saved)
326 mcore_insn_debug (("MCORE: Scanning prologue: func_addr=0x%x, stop=0x%x\n",
327 (unsigned int) func_addr
, (unsigned int) stop
));
330 for (addr
= func_addr
; addr
< stop
; addr
+= 2)
333 insn
= get_insn (addr
);
334 mcore_dump_insn ("got 2: ", addr
, insn
);
338 int offset
= 1 + ((insn
>> 4) & 0x1f);
339 mcore_insn_debug (("MCORE: got subi r0,%d; contnuing\n", offset
));
343 else if (IS_STM (insn
))
345 /* Spill register(s) */
349 /* BIG WARNING! The MCore ABI does not restrict functions
350 to taking only one stack allocation. Therefore, when
351 we save a register, we record the offset of where it was
352 saved relative to the current framesize. This will
353 then give an offset from the SP upon entry to our
354 function. Remember, framesize is NOT constant until
355 we're done scanning the prologue. */
356 start_register
= (insn
& 0xf);
357 mcore_insn_debug (("MCORE: got stm r%d-r15,(r0)\n", start_register
));
359 for (rn
= start_register
, offset
= 0; rn
<= 15; rn
++, offset
+= 4)
361 register_offsets
[rn
] = framesize
- offset
;
362 mcore_insn_debug (("MCORE: r%d saved at 0x%x (offset %d)\n", rn
,
363 register_offsets
[rn
], offset
));
365 mcore_insn_debug (("MCORE: continuing\n"));
368 else if (IS_STWx0 (insn
))
370 /* Spill register: see note for IS_STM above. */
373 rn
= (insn
>> 8) & 0xf;
374 imm
= (insn
>> 4) & 0xf;
375 register_offsets
[rn
] = framesize
- (imm
<< 2);
376 mcore_insn_debug (("MCORE: r%d saved at offset 0x%x\n", rn
, register_offsets
[rn
]));
377 mcore_insn_debug (("MCORE: continuing\n"));
380 else if (IS_MOVx0 (insn
))
382 /* We have a frame pointer, so this prologue is over. Note
383 the register which is acting as the frame pointer. */
384 flags
|= MY_FRAME_IN_FP
;
385 flags
&= ~MY_FRAME_IN_SP
;
386 fp_regnum
= insn
& 0xf;
387 mcore_insn_debug (("MCORE: Found a frame pointer: r%d\n", fp_regnum
));
389 /* If we found an FP, we're at the end of the prologue. */
390 mcore_insn_debug (("MCORE: end of prologue\n"));
394 /* If we're decoding prologue, stop here. */
398 else if (IS_STWxy (insn
) && (flags
& MY_FRAME_IN_FP
) && ((insn
& 0xf) == fp_regnum
))
400 /* Special case. Skip over stack slot allocs, too. */
401 mcore_insn_debug (("MCORE: push arg onto stack.\n"));
404 else if (IS_LRW1 (insn
) || IS_MOVI1 (insn
)
405 || IS_BGENI1 (insn
) || IS_BMASKI1 (insn
))
411 mcore_insn_debug (("MCORE: looking at large frame\n"));
415 read_memory_integer ((addr
+ 2 + ((insn
& 0xff) << 2)) & 0xfffffffc, 4);
417 else if (IS_MOVI1 (insn
))
418 adjust
= (insn
>> 4) & 0x7f;
419 else if (IS_BGENI1 (insn
))
420 adjust
= 1 << ((insn
>> 4) & 0x1f);
421 else /* IS_BMASKI (insn) */
422 adjust
= (1 << (adjust
>> 4) & 0x1f) - 1;
424 mcore_insn_debug (("MCORE: base framesize=0x%x\n", adjust
));
426 /* May have zero or more insns which modify r1 */
427 mcore_insn_debug (("MCORE: looking for r1 adjusters...\n"));
429 insn2
= get_insn (addr
+ offset
);
430 while (IS_R1_ADJUSTER (insn2
))
434 imm
= (insn2
>> 4) & 0x1f;
435 mcore_dump_insn ("got 3: ", addr
+ offset
, insn
);
436 if (IS_ADDI1 (insn2
))
439 mcore_insn_debug (("MCORE: addi r1,%d\n", imm
+ 1));
441 else if (IS_SUBI1 (insn2
))
444 mcore_insn_debug (("MCORE: subi r1,%d\n", imm
+ 1));
446 else if (IS_RSUBI1 (insn2
))
448 adjust
= imm
- adjust
;
449 mcore_insn_debug (("MCORE: rsubi r1,%d\n", imm
+ 1));
451 else if (IS_NOT1 (insn2
))
454 mcore_insn_debug (("MCORE: not r1\n"));
456 else if (IS_ROTLI1 (insn2
))
459 mcore_insn_debug (("MCORE: rotli r1,%d\n", imm
+ 1));
461 else if (IS_BSETI1 (insn2
))
463 adjust
|= (1 << imm
);
464 mcore_insn_debug (("MCORE: bseti r1,%d\n", imm
));
466 else if (IS_BCLRI1 (insn2
))
468 adjust
&= ~(1 << imm
);
469 mcore_insn_debug (("MCORE: bclri r1,%d\n", imm
));
471 else if (IS_IXH1 (insn2
))
474 mcore_insn_debug (("MCORE: ix.h r1,r1\n"));
476 else if (IS_IXW1 (insn2
))
479 mcore_insn_debug (("MCORE: ix.w r1,r1\n"));
483 insn2
= get_insn (addr
+ offset
);
486 mcore_insn_debug (("MCORE: done looking for r1 adjusters\n"));
488 /* If the next insn adjusts the stack pointer, we keep everything;
489 if not, we scrap it and we've found the end of the prologue. */
490 if (IS_SUB01 (insn2
))
494 mcore_insn_debug (("MCORE: found stack adjustment of 0x%x bytes.\n", adjust
));
495 mcore_insn_debug (("MCORE: skipping to new address 0x%x\n", addr
));
496 mcore_insn_debug (("MCORE: continuing\n"));
500 /* None of these instructions are prologue, so don't touch
502 mcore_insn_debug (("MCORE: no subu r1,r0, NOT altering framesize.\n"));
506 /* This is not a prologue insn, so stop here. */
507 mcore_insn_debug (("MCORE: insn is not a prologue insn -- ending scan\n"));
511 mcore_insn_debug (("MCORE: done analyzing prologue\n"));
512 mcore_insn_debug (("MCORE: prologue end = 0x%x\n", addr
));
514 /* Save everything we have learned about this frame into FI. */
517 fi
->extra_info
->framesize
= framesize
;
518 fi
->extra_info
->fp_regnum
= fp_regnum
;
519 fi
->extra_info
->status
= flags
;
521 /* Fix the frame pointer. When gcc uses r8 as a frame pointer,
522 it is really an arg ptr. We adjust fi->frame to be a "real"
524 if (fi
->next
== NULL
)
526 if (fi
->extra_info
->status
& MY_FRAME_IN_SP
)
527 fi
->frame
= read_sp () + framesize
;
529 fi
->frame
= read_register (fp_regnum
) + framesize
;
532 /* Note where saved registers are stored. The offsets in REGISTER_OFFSETS
533 are computed relative to the top of the frame. */
534 for (rn
= 0; rn
< NUM_REGS
; rn
++)
536 if (register_offsets
[rn
] >= 0)
538 fi
->saved_regs
[rn
] = fi
->frame
- register_offsets
[rn
];
539 mcore_insn_debug (("Saved register %s stored at 0x%08x, value=0x%08x\n",
540 mcore_register_names
[rn
], fi
->saved_regs
[rn
],
541 read_memory_integer (fi
->saved_regs
[rn
], 4)));
546 /* Return addr of first non-prologue insn. */
550 /* Given a GDB frame, determine the address of the calling function's frame.
551 This will be used to create a new GDB frame struct, and then
552 INIT_EXTRA_FRAME_INFO and INIT_FRAME_PC will be called for the new frame. */
555 mcore_frame_chain (struct frame_info
* fi
)
557 struct frame_info
*dummy
;
558 CORE_ADDR callers_addr
;
560 /* Analyze the prologue of this function. */
561 if (fi
->extra_info
->status
== 0)
562 mcore_analyze_prologue (fi
, 0, 0);
564 /* If mcore_analyze_prologue set NO_MORE_FRAMES, quit now. */
565 if (fi
->extra_info
->status
& NO_MORE_FRAMES
)
568 /* Now that we've analyzed our prologue, we can start to ask
569 for information about our caller. The easiest way to do
570 this is to analyze our caller's prologue.
572 If our caller has a frame pointer, then we need to find
573 the value of that register upon entry to our frame.
574 This value is either in fi->saved_regs[rn] if it's saved,
575 or it's still in a register.
577 If our caller does not have a frame pointer, then his frame base
578 is <our base> + -<caller's frame size>. */
579 dummy
= analyze_dummy_frame (FRAME_SAVED_PC (fi
), fi
->frame
);
581 if (dummy
->extra_info
->status
& MY_FRAME_IN_FP
)
583 int fp
= dummy
->extra_info
->fp_regnum
;
585 /* Our caller has a frame pointer. */
586 if (fi
->saved_regs
[fp
] != 0)
588 /* The "FP" was saved on the stack. Don't forget to adjust
589 the "FP" with the framesize to get a real FP. */
590 callers_addr
= read_memory_integer (fi
->saved_regs
[fp
], REGISTER_SIZE
)
591 + dummy
->extra_info
->framesize
;
595 /* It's still in the register. Don't forget to adjust
596 the "FP" with the framesize to get a real FP. */
597 callers_addr
= read_register (fp
) + dummy
->extra_info
->framesize
;
602 /* Our caller does not have a frame pointer. */
603 callers_addr
= fi
->frame
+ dummy
->extra_info
->framesize
;
609 /* Skip the prologue of the function at PC. */
612 mcore_skip_prologue (CORE_ADDR pc
)
614 CORE_ADDR func_addr
, func_end
;
615 struct symtab_and_line sal
;
617 /* If we have line debugging information, then the end of the
618 prologue should the first assembly instruction of the first
620 if (find_pc_partial_function (pc
, NULL
, &func_addr
, &func_end
))
622 sal
= find_pc_line (func_addr
, 0);
623 if (sal
.end
&& sal
.end
< func_end
)
627 return mcore_analyze_prologue (NULL
, pc
, 1);
630 /* Return the address at which function arguments are offset. */
632 mcore_frame_args_address (struct frame_info
* fi
)
634 return fi
->frame
- fi
->extra_info
->framesize
;
638 mcore_frame_locals_address (struct frame_info
* fi
)
640 return fi
->frame
- fi
->extra_info
->framesize
;
643 /* Return the frame pointer in use at address PC. */
646 mcore_virtual_frame_pointer (CORE_ADDR pc
, long *reg
, long *offset
)
648 struct frame_info
*dummy
= analyze_dummy_frame (pc
, 0);
649 if (dummy
->extra_info
->status
& MY_FRAME_IN_SP
)
656 *reg
= dummy
->extra_info
->fp_regnum
;
661 /* Find the value of register REGNUM in frame FI. */
664 mcore_find_callers_reg (struct frame_info
*fi
, int regnum
)
666 for (; fi
!= NULL
; fi
= fi
->next
)
668 if (PC_IN_CALL_DUMMY (fi
->pc
, fi
->frame
, fi
->frame
))
669 return generic_read_register_dummy (fi
->pc
, fi
->frame
, regnum
);
670 else if (fi
->saved_regs
[regnum
] != 0)
671 return read_memory_integer (fi
->saved_regs
[regnum
],
675 return read_register (regnum
);
678 /* Find the saved pc in frame FI. */
681 mcore_frame_saved_pc (struct frame_info
* fi
)
684 if (PC_IN_CALL_DUMMY (fi
->pc
, fi
->frame
, fi
->frame
))
685 return generic_read_register_dummy (fi
->pc
, fi
->frame
, PC_REGNUM
);
687 return mcore_find_callers_reg (fi
, PR_REGNUM
);
690 /* INFERIOR FUNCTION CALLS */
692 /* This routine gets called when either the user uses the "return"
693 command, or the call dummy breakpoint gets hit. */
696 mcore_pop_frame (struct frame_info
*fi
)
700 if (PC_IN_CALL_DUMMY (fi
->pc
, fi
->frame
, fi
->frame
))
701 generic_pop_dummy_frame ();
704 /* Write out the PC we saved. */
705 write_register (PC_REGNUM
, FRAME_SAVED_PC (fi
));
707 /* Restore any saved registers. */
708 for (rn
= 0; rn
< NUM_REGS
; rn
++)
710 if (fi
->saved_regs
[rn
] != 0)
714 value
= read_memory_unsigned_integer (fi
->saved_regs
[rn
],
716 write_register (rn
, value
);
720 /* Actually cut back the stack. */
721 write_register (SP_REGNUM
, FRAME_FP (fi
));
724 /* Finally, throw away any cached frame information. */
725 flush_cached_frames ();
728 /* Setup arguments and PR for a call to the target. First six arguments
729 go in FIRST_ARGREG -> LAST_ARGREG, subsequent args go on to the stack.
731 * Types with lengths greater than REGISTER_SIZE may not be split
732 between registers and the stack, and they must start in an even-numbered
733 register. Subsequent args will go onto the stack.
735 * Structs may be split between registers and stack, left-aligned.
737 * If the function returns a struct which will not fit into registers (it's
738 more than eight bytes), we must allocate for that, too. Gdb will tell
739 us where this buffer is (STRUCT_ADDR), and we simply place it into
740 FIRST_ARGREG, since the MCORE treats struct returns (of less than eight
741 bytes) as hidden first arguments. */
744 mcore_push_arguments (int nargs
, value_ptr
* args
, CORE_ADDR sp
,
745 unsigned char struct_return
, CORE_ADDR struct_addr
)
757 stack_args
= (struct stack_arg
*) alloca (nargs
* sizeof (struct stack_arg
));
759 argreg
= FIRST_ARGREG
;
761 /* Align the stack. This is mostly a nop, but not always. It will be needed
762 if we call a function which has argument overflow. */
765 /* If this function returns a struct which does not fit in the
766 return registers, we must pass a buffer to the function
767 which it can use to save the return value. */
769 write_register (argreg
++, struct_addr
);
771 /* FIXME: what about unions? */
772 for (argnum
= 0; argnum
< nargs
; argnum
++)
774 char *val
= (char *) VALUE_CONTENTS (args
[argnum
]);
775 int len
= TYPE_LENGTH (VALUE_TYPE (args
[argnum
]));
776 struct type
*type
= VALUE_TYPE (args
[argnum
]);
779 mcore_insn_debug (("MCORE PUSH: argreg=%d; len=%d; %s\n",
780 argreg
, len
, TYPE_CODE (type
) == TYPE_CODE_STRUCT
? "struct" : "not struct"));
781 /* Arguments larger than a register must start in an even
782 numbered register. */
785 if (TYPE_CODE (type
) != TYPE_CODE_STRUCT
&& len
> REGISTER_SIZE
&& argreg
% 2)
787 mcore_insn_debug (("MCORE PUSH: %d > REGISTER_SIZE: and %s is not even\n",
788 len
, mcore_register_names
[argreg
]));
792 if ((argreg
<= LAST_ARGREG
&& len
<= (LAST_ARGREG
- argreg
+ 1) * REGISTER_SIZE
)
793 || (TYPE_CODE (type
) == TYPE_CODE_STRUCT
))
795 /* Something that will fit entirely into registers (or a struct
796 which may be split between registers and stack). */
797 mcore_insn_debug (("MCORE PUSH: arg %d going into regs\n", argnum
));
799 if (TYPE_CODE (type
) == TYPE_CODE_STRUCT
&& olen
< REGISTER_SIZE
)
801 /* Small structs must be right aligned within the register,
802 the most significant bits are undefined. */
803 write_register (argreg
, extract_unsigned_integer (val
, len
));
808 while (len
> 0 && argreg
<= LAST_ARGREG
)
810 write_register (argreg
, extract_unsigned_integer (val
, REGISTER_SIZE
));
812 val
+= REGISTER_SIZE
;
813 len
-= REGISTER_SIZE
;
816 /* Any remainder for the stack is noted below... */
818 else if (TYPE_CODE (VALUE_TYPE (args
[argnum
])) != TYPE_CODE_STRUCT
819 && len
> REGISTER_SIZE
)
821 /* All subsequent args go onto the stack. */
822 mcore_insn_debug (("MCORE PUSH: does not fit into regs, going onto stack\n"));
823 argnum
= LAST_ARGREG
+ 1;
828 /* Note that this must be saved onto the stack */
829 mcore_insn_debug (("MCORE PUSH: adding arg %d to stack\n", argnum
));
830 stack_args
[nstack_args
].val
= val
;
831 stack_args
[nstack_args
].len
= len
;
837 /* We're done with registers and stack allocation. Now do the actual
839 while (nstack_args
--)
841 sp
-= stack_args
[nstack_args
].len
;
842 write_memory (sp
, stack_args
[nstack_args
].val
, stack_args
[nstack_args
].len
);
845 /* Return adjusted stack pointer. */
849 /* Store the return address for the call dummy. For MCore, we've
850 opted to use generic call dummies, so we simply store the
851 CALL_DUMMY_ADDRESS into the PR register (r15). */
854 mcore_push_return_address (CORE_ADDR pc
, CORE_ADDR sp
)
856 write_register (PR_REGNUM
, CALL_DUMMY_ADDRESS ());
860 /* Setting/getting return values from functions.
862 The Motorola MCore processors use r2/r3 to return anything
863 not larger than 32 bits. Everything else goes into a caller-
864 supplied buffer, which is passed in via a hidden first
867 For gdb, this leaves us two routes, based on what
868 USE_STRUCT_CONVENTION (mcore_use_struct_convention) returns.
869 If this macro returns 1, gdb will call STORE_STRUCT_RETURN and
870 EXTRACT_STRUCT_VALUE_ADDRESS.
872 If USE_STRUCT_CONVENTION retruns 0, then gdb uses STORE_RETURN_VALUE
873 and EXTRACT_RETURN_VALUE to store/fetch the functions return value. */
875 /* Should we use EXTRACT_STRUCT_VALUE_ADDRESS instead of
876 EXTRACT_RETURN_VALUE? GCC_P is true if compiled with gcc
877 and TYPE is the type (which is known to be struct, union or array). */
880 mcore_use_struct_convention (int gcc_p
, struct type
*type
)
882 return (TYPE_LENGTH (type
) > 8);
885 /* Where is the return value saved? For MCore, a pointer to
886 this buffer was passed as a hidden first argument, so
887 just return that address. */
890 mcore_extract_struct_value_address (char *regbuf
)
892 return extract_address (regbuf
+ REGISTER_BYTE (FIRST_ARGREG
), REGISTER_SIZE
);
895 /* Given a function which returns a value of type TYPE, extract the
896 the function's return value and place the result into VALBUF.
897 REGBUF is the register contents of the target. */
900 mcore_extract_return_value (struct type
*type
, char *regbuf
, char *valbuf
)
902 /* Copy the return value (starting) in RETVAL_REGNUM to VALBUF. */
903 /* Only getting the first byte! if len = 1, we need the last byte of
904 the register, not the first. */
905 memcpy (valbuf
, regbuf
+ REGISTER_BYTE (RETVAL_REGNUM
) +
906 (TYPE_LENGTH (type
) < 4 ? 4 - TYPE_LENGTH (type
) : 0), TYPE_LENGTH (type
));
909 /* Store the return value in VALBUF (of type TYPE) where the caller
912 Values less than 32 bits are stored in r2, right justified and
913 sign or zero extended.
915 Values between 32 and 64 bits are stored in r2 (most
916 significant word) and r3 (least significant word, left justified).
917 Note that this includes structures of less than eight bytes, too. */
920 mcore_store_return_value (struct type
*type
, char *valbuf
)
927 value_size
= TYPE_LENGTH (type
);
929 /* Return value fits into registers. */
930 return_size
= (value_size
+ REGISTER_SIZE
- 1) & ~(REGISTER_SIZE
- 1);
931 offset
= REGISTER_BYTE (RETVAL_REGNUM
) + (return_size
- value_size
);
932 zeros
= alloca (return_size
);
933 memset (zeros
, 0, return_size
);
935 write_register_bytes (REGISTER_BYTE (RETVAL_REGNUM
), zeros
, return_size
);
936 write_register_bytes (offset
, valbuf
, value_size
);
939 /* Initialize our target-dependent "stuff" for this newly created frame.
941 This includes allocating space for saved registers and analyzing
942 the prologue of this frame. */
945 mcore_init_extra_frame_info (struct frame_info
*fi
)
948 fi
->pc
= FRAME_SAVED_PC (fi
->next
);
950 frame_saved_regs_zalloc (fi
);
952 fi
->extra_info
= (struct frame_extra_info
*)
953 frame_obstack_alloc (sizeof (struct frame_extra_info
));
954 fi
->extra_info
->status
= 0;
955 fi
->extra_info
->framesize
= 0;
957 if (PC_IN_CALL_DUMMY (fi
->pc
, fi
->frame
, fi
->frame
))
959 /* We need to setup fi->frame here because run_stack_dummy gets it wrong
960 by assuming it's always FP. */
961 fi
->frame
= generic_read_register_dummy (fi
->pc
, fi
->frame
, SP_REGNUM
);
964 mcore_analyze_prologue (fi
, 0, 0);
967 /* Get an insturction from memory. */
970 get_insn (CORE_ADDR pc
)
973 int status
= read_memory_nobpt (pc
, buf
, 2);
977 return extract_unsigned_integer (buf
, 2);
981 _initialize_mcore_tdep ()
983 extern int print_insn_mcore (bfd_vma
, disassemble_info
*);
984 tm_print_insn
= print_insn_mcore
;
987 add_show_from_set (add_set_cmd ("mcoredebug", no_class
,
988 var_boolean
, (char *) &mcore_debug
,
989 "Set mcore debugging.\n", &setlist
),
This page took 0.048894 seconds and 4 git commands to generate.